Ryan, who has been co-starring in the WB sitcom “All About the Andersons,” returns to the role of Matron “Mama” Morton. A veteran of the Broadway and national touring companies of the Kander and Ebb musical, Ryan will stay with the production through Sept. 12.

Ryan joins a cast that includes Brenda Braxton as Velma Kelly, Charlotte d'Amboise as Roxie Hart, P.J. Benjamin as Amos Hart, Norm Lewis as Billy Flynn and D. Sabella as Mary Sunshine. On March 22 Christopher Sieber, who can currently be seen in the ABC-TV series “It’s All Relative,” replaces Lewis as slick lawyer Billy Flynn. Seiber will play the role through May 2.

Roz Ryan made her Broadway debut in the Fats Waller revue Ain't Misbehavin'. She also starred on The Great White Way in Dreamgirls and One Mo' Time and in the national tours of Annie, South Pacific and Blues in the Night. Ryan's film credits include "Went to Coney Island," "Cotton Club" and "Dark Indigo."

Chicago won the Tony for Best Revival of a Musical in 1997 as well as awards for actors Bebe Neuwirth and James Naughton, director Walter Bobbie, lighting designer Ken Billington and choreographer Ann Reinking. The original production was directed and choreographed by the late Bob Fosse.

The Ambassador Theatre is located at 215 West 49th Street.